As someone who had spent most of her life being defined by athleticism, I was at a total loss when I realized I was no longer the lean girl my husband fell in love with.

When I married my husband, I was barely out of my teenage years and a rail-thin 102 lbs. I couldn't fathom a day would come when I would gain considerable weight or have trouble staying fit. Fast forward seven years and three kids, and it's a whole different story.

That once effortlessly skinny physique is now a thing of the past. But so what if I have to work for it? I'm willing to put in the extra effort to stay fit for the sake of my marriage.

If I'm being totally honest, I don't think my husband would love me the same if I gained a significant amount of weight. And if the tables were turned, I wouldn't love him the same, either. I would still love him, yes, but it would be a significant indicator that something was seriously wrong in our relationship if either of us stopped making the effort to stay fit.

We fell in love going on strenuous hikes and training for marathons. We're competitive, strong, and health-conscious. These aren't traits that we can simply decide no longer matter one day. Part of our marriage was built on them. We've banked on physical fitness as part of our future together.

We want to raise our kids to respect their bodies and physical health. I have to practice what I preach. I need to workout for my mental health. I need to stay physically fit to keep up with the demands of raising three kids.

I need to maintain my weight so I feel confident in my body — not because I'm vain, but because I want to be the best version of myself.

No matter how much my husband praises my body, I have to feel comfortable with my body, and I'm most comfortable when I'm skinny. It means I'm taking care of myself and my physical needs because I'm naturally thin when I'm living a healthy lifestyle.

If I feel like I'm out of shape, there's nothing he can say to make me feel sexy. That confidence has to come from within. When I'm lacking that self-confidence, it's so much harder for me to feel sexually attractive, which spells out big problems in the bedroom.

Even though logically know that I'm still deserving of love and physical affection, I put up a barrier between us because I don't feel like I'm deserving. Sex doesn't solely hinge on me being sexually attracted to my husband; I need to feel attractive, too.

As I get older, it's becoming harder to maintain the exact same physique but I've found it's worth the challenge. Focusing on our health together keeps us close and keeps us happy.

It's certainly not the case for everyone, but maintaining a lifestyle that keeps us both fit is important to me. It's not just about maintaining a certain body image but about maintaining an aspect of our relationship that brings us joy.

As our interests evolve over the course of our marriage, we need some constants to bind us together, and this, we've decided, is one of them. And if you ask me, it's a damn good one.